H-4 Unusual Sound Is Heard From Around Hydraulic Pump - Komatsu PC88MR-10 Shop Manual

H-4 Unusual sound is heard from around hydraulic pump

Failure
Related information
No. Cause
Lowering of hydraulic oil level
1
Defective hydraulic oil
2
Clogging of hydraulic tank cap
3
Clogging of hydraulic tank
4
strainer
Clogging of hydraulic tank
5
return filter
Defective piston pump
6
PC88MR-10
Unusual sound is heard from around hydraulic pump
Procedure, measuring location, criteria and remarks
Check hydraulic oil level directly.
(Reference) If the hydraulic oil level is low while no hydraulic oil leaks to
the outside, it is assumed that hydraulic oil may flow in the flywheel
chamber due to a pump shaft seal damage.
Air may mix in hydraulic oil. Check it for bubbles or milky state.
Cap of the hydraulic tank cap may be clogged, causing negative
pressure inside the tank. Check the cap.
Strainer in the hydraulic tank may be clogged, causing negative
pressure in the suction circuit. Check the strainer.
Check the return filter in the hydraulic tank may be clogged, especially
by metallic materials. Check the return filter.
If any metallic materials are detected in Cause 4 and 5 above, piston
pump may have internal defect.
Troubleshooting of hydraulic and mechanical system (H-
40 Troubleshooting
mode)
(PC400-BAA-400-A-Z0-A)
40-469